In the sea, also, the turtles are pursued by man. In the clear West Indian waters, where they are frequently seen at great depths, feeding on the sea-grass meadows, divers plunge after them and raise them to the surface. Sometimes they are harpooned, or even caught sleeping on the waters.
The ancient Romans, who spent such extravagant sums upon dishes repugnant to our taste, seem to have had but little relish for turtle flesh, which otherwise the conquerors of the world might easily have obtained from the Red Sea; for though we read that Vitellius feasted upon the brains of pheasants, and the tongues of nightingales, it is nowhere mentioned, that he ever, like the Lord Mayor of London, set seven hundred tureens of turtle soup before his guests.
On the other hand, they made a very extensive use of tortoise-shell, the produce of the Hawk's-bill turtle (Testudo imbricata) a native both of the American and Asiatic seas, and sometimes, but more rarely, met with in the Mediterranean. The flesh of the animal is not held in any estimation as a food, but the plates of the shell being thicker, stronger, and cleaner than those of any other species, render it of great importance as an article of trade.
"Carvilius Pollio," says Pliny, "a man of great invention in matters pertaining to luxury, was the first who cut the plates of the tortoise for veneering or inlaying." The Romans imported large quantities of this precious article from Egypt, and under the reign of Augustus, the wealthy patricians used even to inlay the doors and columns of their palaces with it. When Alexandria was taken by Julius Cæsar, the warehouses were so full of tortoise-shell that the conqueror proposed to make it the principal ornament of his triumph.
The use of tortoise-shell for the decoration of houses and furniture is long since out of fashion, but it is still in great request for the making of combs and boxes. By steeping it in boiling water it softens, and may then, by a strong pressure, be moulded into any form. When a considerable extent of surface is required, different pieces must be joined together. This is done by scraping thin the edges of the pieces to be united, and laying them over each other while they are in the heated and softened state; strong pressure being then applied, they become completely agglutinated. It is in this way that gold, silver, and other metals for different ornaments are made to adhere to tortoise-shell.